Carburetor for internal-combustion engines



Aug. 11, 1925.

W. H. COLLIER CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed April 9,1925 I INVENTOR. 6 0E167.

ZZi'amH v ATTORNEY Patented Aug. ll, 1925.

UNITED STATES WILLIAM H. COLLIER, 0F JACKSON, TENNESSEE.

CARBURETOR FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 9, 1925.

To all whom it may concern:

Be it known that I, WILLIAM H. COLLIER, a citizen of the United States,residing at Jackson, in the county of Madison and State of Tennessee,have invented certain new and useful Improvements in Carburetors forInternal-Combustion Engines, of which the following is a specification.

This invention relates to carburetors for internal combustion engineswhich are required to work at widely varying speeds and under variableload conditions such as are met with in the operation of auto-.

vehicles.

One of the objects of my invention to provide a carburetor having avariable control element, operable by the usual throttle control leverat the steering wheel, which performs the dual function of a throttlevalve and a variable fuel supply valve and under every condition ofspeed and load delivers a proper fuel mixture to the engine cylinders.One of my purposes is to dispense with the'separate throttle valve andair and fuel control mechanism now used and the necessity for auxiliaryair supply devices and to reduce the entire engine control to a singlemanually controlled element. A further object is to dispense with theuse of a vacuum tank and to connect the carburetor by a pipe leadingdirectly to the gasolene supply tank. To this end I have devised acarburetor which maintains at all times a degree of vacuum, orsub-atmospheric pressure at the jet orifices which varies in accordancewith the controlled speed of the engine and thereby delivers the properquantity of fuel to the vacuum chamber under all of the varyingconditionsof load and engine speed without any tendency to floodingduring an idling period or to produce too rich or too lean a mixtureunder varying speed conditions. Another object is to produce acarburetor which cannot flood or leak under any conditions. A furtherpurpose is to produce a carburetor which will deliver into the engine aless amount of fuel mixture under all conditions of load and speed thancan be obtainedat present and also to furnish a uniform mixture underall conditions.

In the following description I shall refe to the accompanying drawings,in which 2- Figure 1 illustrates the manner in which my carburetor maybe connected to the engine manifold and directly with the fuel SerialNo. 21,828.

supply tank usually secured to the rear of the vehicle; Figures 2 and 3are longitudinal sectional views ofa carburetor embodying my invention;Figure 4 is a longitudinal section of a modified form of my carbure-.

tor; and Figure is an enlarged fragmentary sectional view of the form ofmeterng plug shown in Figure 3; and Figure 6 is a fragmentary enlargedView of the carburetor shown in Figure 2 but with the parts in maximumspeed position.

The carburetor comprises two parts, an inner body portion and an outerrevoluble casing movable longitudinally thereover. The body portion isprovided at one end with a liquid fuel passage 2, internally threadedfor connection to the gasolene line and atthe opposite end with a mainmixing chamber 3, exteriorly threaded for connection' with the. enginemanifold, indicated at 1.

- The fuel passage 2 is connected by a plurality of radiating ducts 4with the circumlar engine being intercalated in said fuel passage, Themain mixing chamber 3 is likewise connectedwith the circumferentialsurface of the body by means of apertures 6 which open into a channel 15formed be-' tween the valve seat 7 and the inner wall of the casing, thechannel 15 constituting a preliminary mixing chamber.

The tapering valve seat 7 lies between the mixture apertures 6 and themonths 4 of the fuel ducts. The inner flaring surface 8 of the casingwhich cooperates with the tapering seat 7 constitutes a throttle valvefor the carburetor. The casing is adjustable longitudinally of thecarburetor body for the purpose of varying the' air intake and fuelsupply. As a means of accomplishing this adjustment I have shown acoarse thread engagement 9, so that the rotation of the casing causes itto travel longitudinally.

Inasmuch as I do not employ a vacuum tank or a float chamber it isessential to subject the liquid column in the gasoline line to asub-atmospheric pressure at all times during the running of the engine.For this purpose the fuel ducts 4 terminate m a vacuum spray chamber 15,constituting) a preliminary mixing chamber 1 formed etween thecarburetor body and an enlarged portion of the casing 8. The air inletis formed between the inner face 13 of a flange extending inwardly fromthe casing, constituting an air valve, and a sloping or taperingcomplementary surface 12 on the body. The inclinations of the throttlevalve seat 7 and of the sloping surface 12 which cooperates with theair-inlet valve 13, bear a definite relation to each other such thatsub-atmospheric pressure in the main mixing chamber 3 remainssubstantially constant for all speeds of the engine while that in thepreliminary mixing chamber 15 increases with the speed of the enginefrom a predetermined minimum to the maximum existing in the mixingchamber. The slant or obliquit of the tapering surface 12 is such thatfor any position of the air valve 13, corresponding to a definite enginespeed, the air inlet permits the ingress of just the proper volume airwhile-the tapering valve seat 7 cooperates with the throttle valve 8 toprovide a passage between the main mixing chamber 3 and the preliminarymixing chamber 15, of such dimensions that the degree of vacuum orsub-atmospheric pressure in the preliminary mixing chamber 15 causes thejets of gasolene issuing from the mouths 4 of the fuel ducts to be soproportioned to the volume of air as to produce the proper mixture inthe chamber 3.

A different rate of opening of these valves is essential to thepreservation of the predetermined minimum sub-atmospheric pressure inthe preliminary mixing chamber 15 and the proportional increase of thesubatmospheric pressure therein as the engine speed increases so thatthe gasolene will be lifted and issue from the jet orifices 4: inproportion to the increase in the volume of air to maintain the properfuel mixture at all speeds. In the particular construction illustratedin the accompanying drawings, I have found that the relativeinclinations of the sloping face 12 of the air inlet and of the seat 7of the throttle valve should be at the respective angles with thelongitudinal axis of the body the ratios of Whose tangents is as 1 to 3.Constructed with these values I have maintained a sub-atmosphericvpressure of substantially 15 inches or 7 pounds in the mainmixing'chamber 3 at all speeds while the sub-atmospheric pressure in thepreliminary mixing chamber 15 surrounding the jet orifices, increasedproportionately with the speed from a minimum of substantially 1 inch toa maximum at full speedof 15 inches.

The valve casing arm 18 to which s connected the link 19 leading to thethrottlecontrol lever and the foot lever at the steering stem Inoperation, the valve casing may be moved to the full choke osition shownin Fig. 3, with the inner edge of the air valve 13 abutting the abutment14, thereby completely cutting 8 is provided with an off the air valve.As the engine is turned over by the starter gasolene 'is drawn throughthe jet orifices 4 and the valve casing is then immediately thrown backto the idling position shown in Figure 2 in which the air and throttlevalves are open only very slightly. The engine speed may then beincreased as desired by rotating the valve casing. When the valves arein the position shown in Figure 6, the maximum speed is attained sincethe annular area between the air valve 13 and the face 12 is then equalto that between the valve 13 and" the abutment 14. At this time thesub-atmospheric pressure in the preliminary mixing chamber 15 is equalto that in the main mixing chamber 3. A continued movement of the valvecasing from this point of maximum valve opening causes the air valveprojection 13 to approach the abutment 14 thereby producing a chokingeffect which increases until the valve casing is in the full chokeposition shown in Figure 3, the richness of the mixture beingcorrespondingly increased.

In Figs. 2 and 6, the fuel ducts 4; are shown as radiating fromthepassage in the metering plug 5. In Figs. 3 and 5, I have shown theplug extending through a threaded aperture into the inner end of themain mixing chamber and provided with an additional fuel duct leadingdirect-1y thereinto. This arrangement is desirable under certainconditions. It is not essential that a metering plug shall be employedas the ducts of the proper bore may be drilled through the metal of thebody as I have shown in Fig. 4. In the latter modification I have alsoshown the body provided with an additional sloping annular surface 20which cooperates with an extension of the casing to form an auxiliaryair inlet valve which may be used in some instances. In the arrangementshown in Fig. 4, the parts areireversed from that shown in Figure 2, sothat the air inlet is adjacent the manifold so that warm air may betaken into the carburetor, and providing a muflling chamber 21.

Because of the characteristics of this carburetor whereby the degree ofvacuum or sub-atmospheric pressure remains substantially constant in themain mixing chamber at all engine speeds, and the mixture is .maintainedsubstantially uniform in density, it is particularly useful in carryingout my method of operating internal combustion engines which involvesthe admission of a combustible mixture to the engine cylinders at auniform sub-atmospheric pressure and which is of less density than thatat present employed, compressing the mixture to a higher compressionthan that now employed, and exhausting at substantially the samepressure as at present. By this method I obtain a hi her mean effectivepressure and increase t e power of the enconsumption of fuel. found thatthe effective cross-sectional area gine with a proportionate decrease inthe Furthermore I-have of the main mixing chamber is much smaller thanin any carburetors heretofore used.

I claim 1. A carburetor for. internal combustioir engines operatingunder varying loads and at variable speeds, having a main mixing chamberadapted to be placed in communication with the engine intake and a pre-'liminar mixing chamber constructed for connection to a' pipe leadin tothe fuel supply tank, an air intake va ve for said preliminary mixingchamber and a throttle valve for said main mixing chamber, said valvesbeing constructed to operate synchronouslv to admit a mixture to saidmain mixing chamber at substantially constant sub-atmospheric pressureat all speeds of theengine, and'to cause a sub-atmospheric ressure insaid preliminary mixing cham r which. varies from a predeterminedminimum at lowest speed to that existing in the main mixing chamber atmaximum speed.

2. A carburetor for'internal combustion engines operatin under varyingloads and at variable spec s, having amain mixing chamber adapted to beplaced incommumcation .with the engine intake and a pre- 7 liminarymixing chamber constructed .for I connect on to a pipe leadin tothe fuelsupply tank, an air intake va ve for said preliminary mixing chamber anda throttle valve for said main mixing chamber, said valves beingconstructed to operate syn'- chronousl to admit a mixture to said m'ainmixing 0 amber at substantially constant sub-atmospheric pressure at allspeeds of the engine, and to'cause asub-atmospheric pressure in saidpreliminary mixing chamber which varies in proportion to the'em ginespeed.

3. A carburetor for internal combustion engines having a main mixingchamber communicating with the engine intake, a

reliminary mixing chamber having. a iquid fuel inlet communicatingtherewith,

an air valve controllin the thro e and air' valve simultaneously, saidthrottle beingsoconetructed that the area ofthe passage between the twomixing chambers is "varied on movement of the H (in-.o'f air. thereto, athrottle valve coated between the two mixin chambers, means foroperating- .mixing'cham r which varies mixing chamber, structed toconcurrently and differently vary the area of the air intake port so asto maintain a varying vacuum in the prelimi-' nary mixing chamber; 4. A'carburetor for variable speed internal combustion engines, comprising abody having a fuel inlet at one end, a main mix- I ing chamber at theopposite end and a preliminary mixing chamber at" anintermediateportion,said body also having fuel ducts connecting said fuel inlet with. saidpreliminary mixing chamber and passages for connecting said preliminarymixing chamher with said mam mixing chamber, a valve seat intermediatesaid chambers, a casing or sleeve movable longitudinally. over said bodyand having valve members for simultaneously controlling in varyingdegrees respectively the admission of .air to said preliminary mixingchamber and to the said. passages connecting said chambers.

5 n a carburetor as set forth in claim 4, said body having a surfacecooperatin with said air intake valve to graduate the intake opening,said surface and said valve. seat being inclined at different anglesrespectively' to the longitudinal axis of the 6. In a carburetor as setforth in claim 4, said body having a surface cooperating with said airintake valve to aduate the. intake openin said surface an' saidvalveseat bein inc ed the longitiliditnflzglieoisthg atan esrespec' tivey 0gen .0 whiZh are ibstantially in the ratio of .one to three.

7. A carburetor for internal combustion engines 0 ratinundervarying'loads and at variabe spee having a mam mixing chamberadapted to be placed m commemcation with the engine intake and a prelimina connection to apipe ly tank, an air iiminary mixing chamber and a,p e valve for said main mixing chamber,-sa1d valves being constructedto operate synchronousl to admit a mixture to said main mixing chamberat substantially constant sub-atmospheric ressure of approximate!one-half. of atmospheric pressure. at a speedsv of the engine, and tocause a sub atmospheric ressure in said, re'limmary '3' determinedlowpressure to that existing in the mixing chamber.

.In testimony whereof leadin tothe fuel sup- 1 afiix my Si n.

while the air valve is con- B0 body.

a. g.'chamber .eonstructed for intake v ve for me AMHQGOLLIE' an

